Patch header in case `session_acad_field_form` is not defined

scipost_django/scipost/templates/scipost/header.html

@@ -9,20 +9,22 @@
         <a href="{% url 'scipost:index' %}"><img src="{% static 'scipost/images/logo_scipost_RGB_HTML_groot.png' %}" class="m-0 p-0" alt="SciPost logo" style="max-width: unset;" width="180" /></a>
       </div>
 
-      <div class="mx-2 my-4 my-lg-auto">
-	<form id="session_acad_field_form" style="display: none;"
-	      hx-get="{% url 'ontology:set_session_acad_field' %}"
-	      hx-trigger="{% if load_header_forms %}load, {% endif %}change"
-	      hx-swap="outerHTML"
+      {% if session_acad_field_form %}
+	<div class="mx-2 my-4 my-lg-auto">
+	  <form id="session_acad_field_form" style="display: none;"
+		hx-get="{% url 'ontology:set_session_acad_field' %}"
+		hx-trigger="{% if load_header_forms %}load, {% endif %}change"
+		hx-swap="outerHTML"
+	  >
+	    {% crispy session_acad_field_form %}
+	  </form>
+	</div>
+	<div class="mx-2 my-4 my-lg-auto"
+	     hx-get="{% url 'ontology:_hx_session_specialty_form' %}"
+	     hx-trigger="{% if load_header_forms %}load, {% endif %}hide.bs.tab from:#home-tab, session-acad-field-set from:body"
 	>
-	  {% crispy session_acad_field_form %}
-	</form>
-      </div>
-      <div class="mx-2 my-4 my-lg-auto"
-	   hx-get="{% url 'ontology:_hx_session_specialty_form' %}"
-	   hx-trigger="{% if load_header_forms %}load, {% endif %}hide.bs.tab from:#home-tab, session-acad-field-set from:body"
-      >
-      </div>
+	</div>
+      {% endif %}
 
       <div class="mt-4 my-lg-auto ms-2">
 	<form id="header-search-form" method="get" action="{% url 'scipost:search' %}">